The effects of tungsten W doping and coating on the electrochemical performance of LiCoO2 cathode are compara- tively studied in this work. The amount of modification component is as low as 0.1 wt% and 0.3 wt% respect...The effects of tungsten W doping and coating on the electrochemical performance of LiCoO2 cathode are compara- tively studied in this work. The amount of modification component is as low as 0.1 wt% and 0.3 wt% respectively. After 100 cycles between 3.0 V-4.6 V, 0.1 wt% W doping provides an optimized capacity retention of 72.3%. However, W coating deteriorates battery performance with capacity retention of 47.8%, even lower than bare LiCoO2 of 55.7%. These different electrochemical performances can be attributed to the surface aggregation of W between doping and coating methods. W substitution is proved to be a promising method to develop high voltage cathodes. Practical performance relies on detailed synthesis method.展开更多
Ba0.8Sr0.2FeO3-δhas been surface-modified by the lithium-ion conductor Li1.4Al0.4Ti1.6(PO4)3via a facile mechanical fusion method. The annealing temperature during coating process shows a strong impact on the surface...Ba0.8Sr0.2FeO3-δhas been surface-modified by the lithium-ion conductor Li1.4Al0.4Ti1.6(PO4)3via a facile mechanical fusion method. The annealing temperature during coating process shows a strong impact on the surface morphology and chemical composition of Li(Ni0.6 Co0.2 Mn0.2)O2. The 600-?C annealed material exhibits the best cyclic stability at high charging cut-off voltage of 4.5 V(versus Li+/Li) with the capacity retention of 90.9% after 100 cycles, which is much higher than that of bare material(79%). Moreover, the rate capability and thermal stability are also improved by Li1.4Al0.4Ti1.6(PO4)3coating. The enhanced performance can be attributed to the improved stability of interface between Ba0.8Sr0.2FeO3-δand electrolyte by Li1.4Al0.4Ti1.6(PO4)3modification. The results of this work provide a possible method to design reliable cathode materials to achieve high energy density and long cycle life.展开更多
基金Project supported by the National Key Rerearch and Development Program of China(Grant No.2017YFB0102004)the National Natural Science Foundation of China(Grant No.51502334)+1 种基金the Fund from Beijing Municipal Science&Technology Commission,China(Grant No.D171100005517001)the Thousand Talent Program for Outstanding Young Scientists,China
文摘The effects of tungsten W doping and coating on the electrochemical performance of LiCoO2 cathode are compara- tively studied in this work. The amount of modification component is as low as 0.1 wt% and 0.3 wt% respectively. After 100 cycles between 3.0 V-4.6 V, 0.1 wt% W doping provides an optimized capacity retention of 72.3%. However, W coating deteriorates battery performance with capacity retention of 47.8%, even lower than bare LiCoO2 of 55.7%. These different electrochemical performances can be attributed to the surface aggregation of W between doping and coating methods. W substitution is proved to be a promising method to develop high voltage cathodes. Practical performance relies on detailed synthesis method.
基金Project supported by the National Key Research and Development Program of China(Grant No.2017YFB0102004)the National Natural Science Foundation of China(Grant No.51822211)the State Grid Technology Project,China(Grant No.DG71-17-010)
文摘Ba0.8Sr0.2FeO3-δhas been surface-modified by the lithium-ion conductor Li1.4Al0.4Ti1.6(PO4)3via a facile mechanical fusion method. The annealing temperature during coating process shows a strong impact on the surface morphology and chemical composition of Li(Ni0.6 Co0.2 Mn0.2)O2. The 600-?C annealed material exhibits the best cyclic stability at high charging cut-off voltage of 4.5 V(versus Li+/Li) with the capacity retention of 90.9% after 100 cycles, which is much higher than that of bare material(79%). Moreover, the rate capability and thermal stability are also improved by Li1.4Al0.4Ti1.6(PO4)3coating. The enhanced performance can be attributed to the improved stability of interface between Ba0.8Sr0.2FeO3-δand electrolyte by Li1.4Al0.4Ti1.6(PO4)3modification. The results of this work provide a possible method to design reliable cathode materials to achieve high energy density and long cycle life.
